Abstract
This review provides a comprehensive overview of the recent advances in the various typical spinel ferrite-based thin films with controlled synthesis, their performances, applications in multifunctional material fields, fundamental scientific challenges, and beyond. Firstly, the crystal structures of spinel ferrite-based thin films are introduced. Secondly, recent progress in traditional synthesizing and novel methods for preparation of spinel ferrite-based films are highlighted. Thirdly, their magnetism, electricity, optics performances, and applications in advanced information technology, energy storage and conversion, and environmental conservation fields are also summarized and discussed in-depth. Some effective strategies for optimizing performances and further applications are summarized. Finally, the present review work ends with a short discussion concerning the challenges, opportunities, and future prospects of spinel ferrite-based thin films.
Introduction
Spinel materials are made of a general formulation of AB2O4, where the A and B are metal ions and comprise of A-O tetrahedron and B-O octahedron. On the basis of distribution of divalent metal ions and Fe3+ on the two cationic sites, spinel materials are mainly classified into three categories such as a normal spinel, inverse spinel, and complex spinel. The trend of interest in spinel materials has grown in recent significant representative research (Schloemann, 2000; Suzuki, 2001; Zhao et al., 2017). Among various spinel materials, spinel ferrites have drawn the attention of researchers owing to their interesting magnetic, electrical, and optical performances. These superior performances are due to high saturation magnetization, low coercivity, high Curie temperature, high electric resistivity, and so on. Spinel ferrites also exhibit intrinsic magnetic, electrical, optical, and catalytic properties originating from their diversiform composition, valence state, and electron configuration. Typical spinel ferrites, including those based on Fe, Ni, Co, Zn, and Mn, have multiple magnetic, electrical, and optical properties for practical applications (Zhao et al., 2017; Li et al., 2019; Du et al., 2020; Pham et al., 2020; Sun et al., 2020; Zhao et al., 2020; Narang and Pubby, 2021).
For spinel ferrite-based thin films, potential applications have been explored in information technology (magnetic sensing and data storage), the electronic industry (resistive switching devices, magnetization switching devices, and spintronic devices), and energy storage fields (supercapacitors, lithium-ion batteries as anodes and cathodes, catalysts, photoelectrodes, and so on) (Suzuki, 2001; Lüders et al., 2006; Wang et al., 2017; Lei et al., 2019; Dongale et al., 2021). It is beneficial for spinel ferrite-based thin films to have manipulated composition, structure, and valence to make them suitable as multifunction materials in various fields. It is worth noting that these thin films have fascinating prospects in some energy conversion storage devices, such as batteries and water splitting, benefitting from their low prices and environmental friendliness (Vadiyar et al., 2016a; Han et al., 2016; Jiang et al., 2018; Nikam et al., 2020).
Given the rapid development of spinel materials, both the preparation and application of spinel ferrite-based thin films have achieved tremendous increasing progress with decades of research. Review articles that cover the most recent developments are urgently needed. However, there has been no comprehensive review of this hot topic. Herein, the recent significant representative preparation and application of spinel ferrite-based thin films are systematically summarized. This review article is divided into the following parts. Firstly, the basic compositions and crystal structural characteristics of spinel ferrite materials are introduced. With the overall understanding of spinel ferrite materials, the synthesis of typical spinel ferrite-based (Ni-based, Co-based, Zn-based, and Mn-based) thin films are systematically reviewed. The solid, solution, and vapor phase methods are discussed. Further, the traditional synthesis and novel methods of spinel ferrite-based thin films are also highlighted. Secondly, magnetic, electrical, and optical properties, and applications are summarized. In addition, some effective strategies for optimizing performance and application are summarized. Finally, fundamental scientific challenges and fascinating prospects are focused on. Some recommendations are put forward to address current challenges and future prospects. Future development will expect to concentrate on advanced electric information technology, energy storage and conversion, and environmental conservation fields, which are challenging issues. From this aspect, more research interests will concentrate upon the exploration of innovative multifunctional spinel ferrite-based thin films with insight into the effect between the structure and property relationship of spinel ferrite-based thin films and elevating the application in various fields.
The Structures and Synthesis Methods of Spinel Ferrite-Based Thin Films
Typical spinel ferrite is briefly described as AFe2O4 (where A = Fe, Ni, Co, Mn, Zn, etc.), these are composed of 32 oxygen atoms with 32 trivalent octahedral sites and 64 divalent tetrahedral sites. Particularly, A2+ and Fe3+ normally take up 16 octahedral sites and eight tetrahedral sites to maintain an electrically balanced state, respectively (Zhao et al., 2017; Narang and Pubby, 2021). Spinel ferrite can be classified into three different types depending on their situations of cation distribution: normal, inverse, and complex spinel as shown in Figure 1A, respectively. In the normal typical spinel ferrite structure, A2+ cations occupy tetrahedral sites, whereas Fe3+ cations occupy octahedral sites, as can be seen in ZnFe2O4, and CdFe2O4. For the inverse spinel ferrite structure, A2+ cations only occupy octahedral sites, however, Fe3+ cations are equally located at tetrahedral and octahedral sites, examples are Fe3O4, NiFe2O4, and CoFe2O4. For complex spinel ferrite structure, A2+ and Fe3+ cations are randomly located at tetrahedral and octahedral sites, i.e., MnFe2O4 or MgFe2O4 (Zhao et al., 2017; Pham et al., 2020).
FIGURE 1
(A) Illustration of the structures of spinel, (B) future development of spinel compounds, applications, preparations, and fundamental challenges. Reproduced from Zhao et al. (2017) with permission from the American Chemical Society.
In the preparation of spinel materials, the majority of methods involve chemical and physical transitions (Zhao et al., 2017). Herein, we summarize the traditional and innovative synthesis approaches of typical spinel ferrite-based thin films, including solid phase methods, solution phase methods, and vapor phase methods. The solid phase approaches consist of combustion, pulsed laser and decomposition methods, and so on (Suzuki, 2001; Hao et al., 2018a; Nikam et al., 2020). The solution phase approaches contain chemical solution deposition, sol-gel, solvothermal, and electro-chemical methods, etc. The vapor phase approaches involve magnetron sputtering, atomic layer deposition, and chemical vapor deposition, etc. The structure, morphology, defects, and loading substrate of spinel ferrite-based thin films have been designed on basis of the above controlled synthesis methods (Suzuki, 2001; Zhao et al., 2017). Among these synthesis approaches, sol-gel is a mild approach and has been widely employed in synthesizing spinel ferrite-based thin films. Generally speaking, metal salts are used to form precursors. Ethylene glycol, glacial acetic acid, or citric acid are adopted as a chelation agent. These reactants are mixed uniformly in the solvents. Then, hydrolysis, condensation, and other reactions occur to form transparent sol systems. The sol gradually turns into gel via the loss of fluid solvent during the aging process. Finally, the compounds are obtained through the calcination process (Ismail et al., 2018; Choueikani et al., 2021; Zhao et al., 2021).
During the development of spinel ferrite-based thin films synthesis, some other innovative technologies can be adopted such as ultrasound-assisted sol-gel, metallo-organic decomposition, and dip-coating methods, etc. Increasing numbers of methods have been found, and novel spinel ferrite-based materials have been synthesized. The structure, morphology, and loading substrates of spinel ferrite-based thin films could be rationally designed and applied in various fields. Table 1 summarizes the main methods reported to synthesize typical spinel ferrite-based thin films. Moreover, their performance (magnetism, electricity, and optics) and typical application examples are listed for comparison.
TABLE 1
| Spinel ferrite-based films | Synthesis methods | Performance | Applications | Performance metrics | References |
|---|---|---|---|---|---|
| Fe3O4 | Molecular beam epitaxy | Magnetism | Magnetization switching | Magnetic moment (3–5 µB/f.u.) | Huang et al. (2015) |
| Saturation magnetization (250–500 emu/cc) | |||||
| Fe3O4 | Electrochemical anodization | Electricity | Lithium-ion batteries | Specific capacity (1,100, 880 and 660 mA h/g at 0.1, 0.2, and 0.5 C) | Cheng et al. (2012) |
| Cycling capability (100 cycles at 0.1 C) | |||||
| Fe3O4 | Deposition | Electricity | Resistive switching | Off/on resistance ratio (∼200 at 20 nm) | Ishibe et al. (2020) |
| NiFe2O4 | RF sputtering | Magnetism | Spintronics devices | Spin-polarization (42%) | Lüders et al. (2006) |
| Spin-filtering efficiency (23% at low temperature) | |||||
| NiFe2O4 | Chemical solution deposition | Electricity | Resistive switching devices | Reset and set voltages (0.8 ± 0.2 and 2.0 ± 0.2 V) | Hu et al. (2012b) |
| Retention time (104 s) endurance (2.2 × 104 cycles) | |||||
| NiFe2O4 | Co-precipitation | Electricity | Aqueous battery | Specific capacity (18.56 mA h/g at 1 mA/cm2) Potential window (0.2–1 V) | Dongale et al. (2021) |
| NiFe2-xGdxO4 | Sol-gel | Optics, magnetism | Functional material | Optical band gap (2.58–2.75 eV) | Yao et al. (2021) |
| Saturation magnetization (70.51–145.29 emu/cc) | |||||
| Coercive field (87.57–154.05 Oe) | |||||
| CoFe2O4 | Atomic layer deposition | Magnetism | Advanced devices | Saturation magnetization (450 emu/cc at 10 nm, 230 emu/cc at 5 nm) | Coll et al. (2014) |
| Coercive fields (15 kOe at 10 nm, 11 kOe at 5 nm) | |||||
| CoFe2O4 | Pulse laser-deposited | Magnetism | Spintronic devices | Saturation magnetization (457 kA/m, 474, and 697 kA/m at 30, 45, and 60 min) anisotropy (290 kJ/m3 with (1 0 0) easy direct) | Eskandari et al. (2019) |
| CoFe2O4 | Chemical vapor deposition | Electricity | Supercapacitor | Capacitance (540 mF/cm2) capacitance retention (80% after 7,000 cycles) | Sagu et al. (2017) |
| CoFe2O4 | Liquid phase epitaxy | Electricity | Electrocatalyst | Overpotential (266 mV at 10 mA/cm2) | Lei et al. (2019) |
| Tafel slope (53 mV/dec) | |||||
| Double layer capacitance (10.9 mF/cm2) | |||||
| CoFe2O4 | Pulse laser-deposited | Electricity | Supercapacitor | Specific capacitance (777.4 F/g) | Nikam et al. (2020) |
| Power density (3,277 W/kg) | |||||
| Energy density (17 W h/kg) | |||||
| Cyclic stability (125% after 1,500 cycles) | |||||
| CoFe2O4-silica | Sol-gel | Optics, magnetism | Magneto-optical | Specific Faraday rotation (310°/cm at 1,550 nm) | Choueikani et al. (2021) |
| Modal birefringence (order of 104) | |||||
| Figure of merit (2°/dB at 1,550 nm) | |||||
| ZnFe2O4 | RF sputtering | Magnetism | Functional material | Saturation magnetization (13–18 emu/cc) | Raghavan et al. (2015) |
| ZnFe2O4 | Mechanochemical | Electricity | Supercapacitor | Specific capacitance (433 F/g) | Vadiyar et al. (2016b) |
| Energy density (86 Wh/kg) | |||||
| Cycling stability (91% retention up to 4,000 cycles) | |||||
| CdS/ZnFe2O4/ZnIn2S4 | Solvothermal processes, ionic layer adsorption reaction | Optics, electricity | Photocatalytic | H2 production rate (79 μmol/h) | Chen et al. (2017) |
| ZnFe2O4-carbon black | Auto-combustion | Electricity | Lithium-ion battery | Specific capacity (560 mA h/g at 0.5 A/g and 330 mA h/g at 3.5 A/g after 100 cycles) | Das et al. (2018) |
| Coulombic efficiency (98%) | |||||
| ZnFe2O4 | Sol-gel method | Electricity | Resistive switching | Set voltages (0.9–2.8 V) | Ismail et al. (2018) |
| Retention time (104 s) Endurance (∼200 cycles) | |||||
| ZnFe2O4 | Pulsed laser deposition | Optics, electricity | Photoelectrodes | Activation energies (170–210 meV) | Henning et al. (2019) |
| Photocurrent onset potential (0.8 V vs. RHE) | |||||
| Co-ZnFe2O4 | Hydrothermal reaction | Optics, electricity | Photoelectrochemical water splitting | Optical band gap (1.97 eV) | Lan et al. (2020) |
| Hydrogen evolution rate (0.0088 μmol/cm2 min) | |||||
| Oxygen evolution rate (0.0038 μmol/cm2 min) | |||||
| MnFe2O4 | Sol-gel, metallo-organic decomposition | Magnetism | Functional material | Saturation magnetization (5.4 emu/cc) | Chand Verma et al. (2011) |
| Remanent magnetization (1.1 emu/cc) | |||||
| Coercive fields (113.3 Oe) | |||||
| MnFe2O4 | Pulsed laser-deposited | Magnetism | Functional material | Magnetic moment (4.6 µB/f.u) | Rajagiri et al. (2018) |
| Exchange stiffness constant 106–168 e effective saturation magnetization (1.1–4.2 kg) | |||||
| MnFe2O4/(Pb1-xSrx)TiO3 | Metal-organic reaction | Electricity, magnetism | Magnetoelectric material | Saturation magnetization (109–119 emu/cc) | Bala et al. (2017) |
| Remanent magnetization (3.6–4 emu/cc) | |||||
| Coercive fields (101–102 Oe) | |||||
| Magnetoelectric coefficient (2.82–4.29 V/Oe cm) |
Comparison of the synthesis methods, performance (magnetism, electricity, and optics), typical application examples, and performance metrics for typical spinel ferrite-based thin films.
In addition, exploring facile methods to synthesize novel spinel ferrite-based thin films remains challenging. The representation methods will benefit the deep understanding of spinel ferrite materials’ performance and application. The fundamental scientific challenge will inspire the exploration of novel synthesis methods. At the same time, novel characterization methods and instruments need be developed to further in-depth understanding of spinel ferrite-based thin films synthesis, performance, and applications in various fields.
Performances and Applications of Spinel Ferrite-Based Thin Films
Spinel ferrite is a class of magnetic materials, where its name results from its similarity with the naturally occurring MgAlO4 mineral. Magnetic properties of spinel ferrite-based thin films contain ferro-, ferri-, para-, anti-ferro-, and diamagnetisms (Zhao et al., 2017). Most Fe, Co, and Ni-based compositions exhibit ferrimagnetism. The magnetic performance of typical spinel ferrite-based thin films could be applied for information technology fields in data storage, magnetization switching devices, spintronic devices, and functional materials (Suzuki, 2001; Lüders et al., 2006; Coll et al., 2014; Huang et al., 2015; Zhao et al., 2017; Eskandari et al., 2019; Yao et al., 2021). For example, typical ferrimagnetic NiFe2O4 thin films were prepared using RF sputtering on SrTiO3-based substrates. It is reported that these films present remarkable enhanced magnetic moments in comparison with bulk substrates, and the electronic performance has been modulated from conducting to insulating by changing the growth conditions, which has meant that these films have been proposed for potential application in spintronics devices (Lüders et al., 2006). In addition, pulse laser-deposited CoFe2O4 thin films also exhibited a change in the saturation magnetization, coercivity, and magnetic anisotropy for magnetic oxide-based spintronic devices application (Eskandari et al., 2019). Moreover, the magnetism of typical ZnFe2O4 and MnFe2O4-based thin films have also been investigated for tuning the saturation magnetization, coercivity, magnetic moment, Curie temperature, and magnetic anisotropy properties (Chand Verma et al., 2011; Raghavan et al., 2015; Bala et al., 2017; Rajagiri et al., 2018). These favorable magnetic properties of spinel ferrite-based thin films have made them an eye-catcher for material science researchers. Therefore, these ferrite materials are desired to further widen their application range in magneto-electric and magneto-optical fields.
Electrical performance and application of spinel ferrite-based thin films, especially in emerging random access memories and energy storage devices, have recently achieved great attention owing to the shortcomings of Flash memories and increasing fossil energy consumption. The spinel ferrite-based thin films have also been applied in many storage fields, such as resistive random access memory, supercapacitors, Li-ion batteries, electrocatalysts, and so on (Hu et al., 2012a; Wang et al., 2013; Hu et al., 2014; Hwang et al., 2017; Sagu et al., 2017; Jiang et al., 2018; Nikam et al., 2020; Dongale et al., 2021). Spinel ferrite-based resistive switching materials are one of a few promising resistive random access memory candidates. Large fluctuating resistance states, degradation of endurance and retention time, and the controversial physical mechanism in practical applications are challenging reliability issues that need to be solved. Many efforts have been made to enhance the performance of resistive switching devices to satisfy the requirements of commercial applications, such as impurity doping, introduction of metal nanoparticles, interface engineering, and bilayer structure (Pan et al., 2014). Recently, Fe3O4, NiFe2O4, CoFe2O4, and ZnFe2O4-based films, un-doped or doped with various valence elements (Ce, Gd, Cr, Cu etc.), have demonstrated remarkable improvements in their resistive switching characteristics (Hu et al., 2012a; Hu et al., 2012b; Hu et al., 2014; Hao et al., 2017a; Hao et al., 2018b; Hao et al., 2019a; Hao et al., 2019b; Ishibe et al., 2020). For example, NiFe2O4-based memory devices presented enhancement for resistive switching characteristics, such as a reduction of set/reset voltage, favorable endurance and data retention time via partial substitution of Fe3+ with trivalent Gd3+, Ce3+, or Cr3+ doping, or partial substitution of Ni2+ with divalent Cu2+ doping (Hao et al., 2017a; Hao et al., 2018b; Hao et al., 2019a). Moreover, related magnetism of NiFe2O4 thin films has been modulating by impurity doping and introducing metal nanoparticles (Ag or Au). It is worth noting that Bao’s group made significant contributions in the spinel ferrite-based resistive switching materials research. They effectively improved the resistive switching performances and clarified the switching mechanism by various modification methods (Hao et al., 2017b; Hao et al., 2018a; Hao et al., 2018c). In addition, coexistence behavior of resistive and magnetization switching of ferrite-based thin films have inspired much attention in the scientific world and the business community for promoting data storage density. The resistive and magnetization switching has been achieved in devices through the manipulation of applied electric fields in which a Cr-doped NiFe2O4 switching layer was prepared via a facile chemical solution deposition approach (Hao et al., 2019a). The above devices presented stable operating voltage, prominent endurance (>103 cycles), large on/off memory window (>102), and superior retention time (>105 s at 25°C). Moreover, the saturation magnetization of the devices exhibited reversible switching in different resistance states for promising application in resistive and magnetization switching devices. This behavior provides a deeper insight into the potential applications in nonvolatile memory and magneto-electric coupling devices. Moreover, the challenges of further boosting property and application in memory, energy storage devices, and outlook for future innovative research directions are also anticipated.
Supercapacitors, such as typical electrochemical capacitors, have been regarded as one of the most promising candidates in energy storage fields resulting from their superior advantages (high power density, lower cost, and long life, etc.) (Li et al., 2019). Electrode materials have a vital role in the performance of supercapacitors. Therefore, many studies concentrated on exploring novel electrode materials for high performance supercapacitors. For the past few years, spinel ferrite-based thin films as supercapacitors electrode materials have gained much attention owing to their outstanding advantages, such as ease of synthesis, low cost, and high theoretical capacity (Li et al., 2012; Jiang et al., 2018; Nikam et al., 2020). The pulsed laser-deposited CoFe2O4 films exhibited enhanced electrochemical property and supercapacitor electrode performance, such as superior power density (3,277 W kg−1), energy density (17 W h kg−1), and cyclic stability (125% after 1,500 cycles) (Nikam et al., 2020). Additionally, the comparative research of individual and mixed aqueous electrolytes with ZnFe2O4 nano-flake film electrodes in a supercapacitors application has also been investigated (Vadiyar et al., 2016b). Although the spinel ferrite-based thin film supercapacitors show high performance, there are still some challenges to be addressed before commercialization.
In comparison with supercapacitors, batteries generally possess higher energy density and operating voltage (Pham et al., 2020). However, some challenges such low capacity, poor cycling stability, and limited low-temperature performances impose restrictions on their commercial applications in hybrid vehicles and energy storage devices. Recent efforts have been focused on investigating the electrochemical performance of spinel ferrite-based thin films as both anodes and cathodes for rechargeable lithium-ion and aqueous batteries (Cheng et al., 2012; Wang et al., 2013; Wang et al., 2015; Hwang et al., 2017; Choi et al., 2018; Das et al., 2018; Huang et al., 2020; Dongale et al., 2021). For example, rugated porous Fe3O4 films as high-performance anode materials presented a specific capacity of 1,100, 880, and 660 mA h g−1 at 0.1, 0.2, and 0.5 C, respectively, a stable charge/discharge platform, and high cycling stability (Cheng et al., 2012). Moreover, ZnFe2O4-carbon black porous film-derived superior negative electrodes for a lithium-ion battery have been investigated, which delivered a steadily reversible specific capacity of 560 mA h g−1 at 0.5 A g−1, which maintained for approximately 100 cycles. The above electrodes also presented a 330 mA h g−1 specific capacity at 3.5 A g −1 (Das et al., 2018). For future work on spinel ferrite-based thin film batteries, effective strategies, such as doping, carbon coating, and multi-electrode designing, is suggested to further boost electrochemical performance and insight into advanced mechanism of spinel ferrite-based thin films. Moreover, some perspectives and critical challenges for future spinel ferrite-based thin films research also deserve to be explored and addressed.
In addition, spinel compounds have been widely investigated as catalysts in various fields. Hydrogen and oxygen evolution reactions are major reactions in water splitting, which were mentioned as a major approach to generate H2 for clean energy (Zhao et al., 2017). Spinel ferrite-based thin films can be used as electrocatalysts in water splitting and energy convention storage (Kumbhar et al., 2015; Han et al., 2016; Sagu et al., 2018; Lei et al., 2019; Lan et al., 2020). For example, well-aligned mesoporous CoFe2O4 films have been developed by surface epitaxial growth for an efficient electrocatalytic oxygen evolution reaction. It is interesting that the self-support CoFe2O4 film electrodes delivered an overpotential of 266 mV in oxygen evolution at a 10 mA cm−2 current density and exhibited good stability. The obvious and steady catalytic property of CoFe2O4 films was ascribed mainly to the mesoporous structures, the numerous exposed active sites, and efficient charge/electron transfer (Lei et al., 2019). Electrospray technique-derived ZnFe2O4 thin films with photo-absorber material for photoelectrochemical water splitting were fabricated and were found to increase discharge potential, induce more active sites, and enhance the photocurrent of 53 μAcm−2 at 1.23 V versus RHE (Wang et al., 2017). In addition, innovative p-type Co-doping ZnFe2O4 films, as prospective cathodes for photoelectrochemical water splitting, were prepared via hydrothermal reaction and sintering treatment, in which the photocurrent density was 0.22 mA cm−2 at 0 V vs. RHE with improvement by about 7.33-fold compared with that of the n-type ZnFe2O4 (0.03 mA cm−2 at 0 V vs. RHE) (Lan et al., 2020). Given the advantages of spinel ferrite-based thin films, further optimization and development in electrocatalytic performance is highly desired. Some effective strategies including electronic structure regulation, micro-structure engineering, and phase and composition modulation need to be further explored and adopted to regulate the electrocatalytic performance of spinel ferrite-based thin films.
It is worth noting that some spinel ferrite-based thin films exhibited unique optical characteristics, such as absorption, optical bands, birefringence, and Faraday rotation, which have been adopted for magneto-optical recording devices and photocatalysts (Li et al., 2010; Bharathi et al., 2011; Chen et al., 2017; Chavan et al., 2019; Henning et al., 2019; Yu et al., 2019; Labchir et al., 2020; Lan et al., 2020; Choueikani et al., 2021). For example, low index magneto-optical CoFe2O4-silica nanocomposite thin films were fabricated using the composite method and presented an intrinsic Faraday rotation of 310°/cm at 1,550 nm for an NP 1.5% volume fraction, and the modal birefringence was the order of 10–4 (Choueikani et al., 2021). Moreover, the ZnFe2O4 samples showed the best photocatalytic performance for degradation of Orange II dye (100% after 180 min) (Yu et al., 2019). Although the ferrite-based thin films have potential and cost-effective advantages as adsorbent photocatalysts to remove environmental contaminants, the related research is still lacking and limited. Furthermore, the large-scale application and long-term sustainability remain challenging issues. As a result, it encourages more investigations to solve these challenging issues by designing novel spinel ferrite-based thin film materials and improve treatment technology in water remediation technology and environmental conservation areas.
Fundamental Scientific Challenges and Beyond
In recent decades, the compositions, synthesis, performance, and application of spinel ferrite-based thin films have seen rapid development (Table 1). Future research would continue to enrich spinel ferrite systems, developing novel synthesis methods and expanding the application fields. The future applications of spinel ferrite materials are shown in Figure 1B (Zhao et al., 2017). Over the past decades, the progress of research in this field has been extremely noteworthy and significant. However, at present, investigations into spinel ferrite-based thin films are limited. Other spinel ferrite-based thin films will deserve investigation in the future. Meanwhile, exploring innovative inorganic-organic hybrid spinel ferrite-based thin films is also a novel path to widen the spinel ferrite-based thin film systems.
Moreover, the majority of novel synthesis methods can be adopted to fabricate spinel ferrite-based thin films, whereas the preparation is still limited. To explore a facile path to prepare spinel ferrite-based thin films beyond traditional methods remains challenging. The in-situ technique to investigate the relationship of structure, property, mechanism, and application of spinel ferrite-based thin films is still less understood. At the same time, novel characterization methods and instruments need to be introduced for better understanding of spinel ferrite-based thin film performance. The future application development of spinel ferrite-based thin films is also challenging. Consequently, future breakthroughs to overcome the aforementioned challenging issues are highly desirable. These fundamental scientific challenges will offer impetus in exploring novel synthesis methods, optimizing performances, and development application of spinel ferrite-based thin films. Further efforts are supposed to concentrate on advanced electric information technology, energy storage and conversion, and environmental conservation fields (Zhao et al., 2017; Chandrasekaran et al., 2018; Pham et al., 2020; Sun et al., 2020; Carlos et al., 2021; Liu et al., 2021). Therefore, this fundamental scientific challenge deserves more attention and stimulates research activity in these research fields. It is believed that this review will lay the path for development of spinel ferrite-based films in future technology.
Conclusion
In summary, the developments of controlled synthesis, magnetic, electrical, and optical properties, applications in multifunctional material fields, and beyond for various typical spinel ferrite-based thin films were summarized. The composition and structures of spinel ferrite-based thin films were introduced. Recent advances in the synthesis of spinel ferrite-based films methods were highlighted. The performances of magnetism, electricity, and optics were also summarized. The magnetism, electricity, and optics applications in advanced information technology, energy storage and conversion, and environmental conservation fields were also reviewed. We also presented discussion concerning the challenges and future prospects of spinel ferrite-based films. Some recommendations were put forward to address the current challenges and future prospects.
Statements
Author contributions
AH and XN wrote the manuscript. AH supervised and edited the manuscript.
Funding
The authors gratefully acknowledge financial support from the National Natural Science Foundation of China (No. 12064042), the Talent Program of Tianshan Youth of Xinjiang Autonomous Region (No. 2020Q070), the Natural Science Foundation of Xinjiang Autonomous Region (No. 2020D01C054), the Scientific Research Program of Higher Education Institution of Xinjiang (No. XJEDU2020Y007), the Tianchi Doctoral Project of Xinjiang Autonomous Region (No. tcbs201807), and the PhD Research Startup Foundation of Xinjiang University (No. BS180276).
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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References
1
BalaK.KotnalaR. K.NegiN. S. (2017). Magnetically Tunable Dielectric, Impedance and Magnetoelectric Response in MnFe2O4/(Pb1−xSrx)TiO3 Composites Thin Films. J. Magnetism Magn. Mater.424, 256–266. 10.1016/j.jmmm.2016.10.059
2
BharathiK. K.VemuriR. S.RamanaC. V. (2011). Dysprosium-substitution Induced Changes in the Structure and Optical Properties of Nickel Ferrite (NiFe2O4) Thin Films. Chem. Phys. Lett.504, 202–205. 10.1016/j.cplett.2011.02.003
3
CarlosE.BranquinhoR.MartinsR.KiazadehA.FortunatoE. (2021). Recent Progress in Solution-Based Metal Oxide Resistive Switching Devices. Adv. Mater.33, 2004328. 10.1002/adma.202004328
4
Chand VermaK.Pratap SinghV.RamM.ShahJ.KotnalaR. K. (2011). Structural, Microstructural and Magnetic Properties of NiFe2O4, CoFe2O4 and MnFe2O4 Nanoferrite Thin Films. J. Magnetism Magn. Mater.323, 3271–3275. 10.1016/j.jmmm.2011.07.029
5
ChandrasekaranS.BowenC.ZhangP.LiZ.YuanQ.RenX.et al (2018). Spinel Photocatalysts for Environmental Remediation, Hydrogen Generation, CO2 Reduction and Photoelectrochemical Water Splitting. J. Mater. Chem. A.6, 11078–11104. 10.1039/c8ta03669a
6
ChavanA. R.BabrekarM. K.NawleA. C.JadhavK. M. (2019). Impact of Trivalent Metal Ion Doping on Structural, Photoluminescence and Electric Properties of NiFe2O4 Thin Films. J. Elec Materi48, 5184–5194. 10.1007/s11664-019-07329-w
7
ChenY.TianG.ZhouW.XiaoY.WangJ.ZhangX.et al (2017). Enhanced Photogenerated Carrier Separation in CdS Quantum Dot Sensitized ZnFe2O4/ZnIn2S4 Nanosheet Stereoscopic Films for Exceptional Visible Light Photocatalytic H2 Evolution Performance. Nanoscale9, 5912–5921. 10.1039/c7nr00155j
8
ChengH.LuZ.MaR.DongY.WangH. E.XiL.et al (2012). Rugated Porous Fe3O4 Thin Films as Stable Binder-free Anode Materials for Lithium Ion Batteries. J. Mater. Chem.22, 22692. 10.1039/c2jm34373h
9
ChoiM.LeeS.-H.JungY.-I.ChoiW.-K.MoonJ.-K.ChoiJ.et al (2018). The Preparation of Fe3O4 Thin Film and its Electrochemical Characterization for Li-Ion Battery. Trans. Electr. Electron. Mater.19, 417–422. 10.1007/s42341-018-0062-4
10
ChoueikaniF.JamonD.NeveuS.Blanc-MignonM.-F.LefkirY.RoyerF. (2021). Self-biased Magneto-Optical Films Based on CoFe2O4-Silica Nanocomposite. J. Appl. Phys.129, 023101. 10.1063/5.0032620
11
CollM.Montero MorenoJ. M.GazquezJ.NielschK.ObradorsX.PuigT. (2014). Low Temperature Stabilization of Nanoscale Epitaxial Spinel Ferrite Thin Films by Atomic Layer Deposition. Adv. Funct. Mater.24, 5368–5374. 10.1002/adfm.201400517
12
DasD.MitraA.JenaS.MajumderS. B.BasuR. N. (2018). Electrophoretically Deposited ZnFe2O4-Carbon Black Porous Film as a Superior Negative Electrode for Lithium-Ion Battery. ACS Sust. Chem. Eng.6, 17000–17010. 10.1021/acssuschemeng.8b04332
13
DongaleT. D.KhotS. S.PatilA. A.WaghS. V.PatilP. B.DubalD. P.et al (2021). Bifunctional Nanoparticulated Nickel Ferrite Thin Films: Resistive Memory and Aqueous Battery Applications. Mater. Des.201, 109493. 10.1016/j.matdes.2021.109493
14
DuY.ShengH.AstrucD.ZhuM. (2020). Atomically Precise Noble Metal Nanoclusters as Efficient Catalysts: A Bridge between Structure and Properties. Chem. Rev.120, 526–622. 10.1021/acs.chemrev.8b00726
15
EskandariF.KameliP.SalamatiH.EsmaeilyA. S. (2019). Tuning the Exchange Coupling in Pulse Laser Deposited Cobalt Ferrite Thin Films by Hydrogen Reduction. J. Magnetism Magn. Mater.484, 188–195. 10.1016/j.jmmm.2019.03.133
16
HanS.LiuS.YinS.ChenL.HeZ. (2016). Electrodeposited Co-doped Fe3O4 Thin Films as Efficient Catalysts for the Oxygen Evolution Reaction. Electrochimica Acta210, 942–949. 10.1016/j.electacta.2016.05.194
17
HaoA.HeS.QinN.ChenR.BaoD. (2017). Ce-doping Induced Enhancement of Resistive Switching Performance of Pt/NiFe2O4/Pt Memory Devices. Ceramics Int.43, S481–S487. 10.1016/j.ceramint.2017.05.214
18
HaoA.IsmailM.HeS.HuangW.QinN.BaoD. (2018). Coexistence of Unipolar and Bipolar Resistive Switching Behaviors in NiFe2O4 Thin Film Devices by Doping Ag Nanoparticles. J. Appl. Phys.123, 085108. 10.1063/1.5018808
19
HaoA.IsmailM.HeS.QinN.ChenR.RanaA. M.et al (2018). Enhanced Resistive Switching and Magnetic Properties of Gd-Doped NiFe2O4 Thin Films Prepared by Chemical Solution Deposition Method. Mater. Sci. Eng. B229, 86–95. 10.1016/j.mseb.2017.12.025
20
HaoA.IsmailM.HeS.QinN.HuangW.WuJ.et al (2017). Ag-NPs Doping Enhanced Resistive Switching Performance and Induced Changes in Magnetic Properties of NiFe2O4 Thin Films. RSC Adv.7, 46665–46677. 10.1039/c7ra08756j
21
HaoA.IsmailM.HeS.QinN.HuangW.WuJ.et al (2018). Improved Unipolar Resistive Switching Characteristics of Au-Doped Nickel Ferrite Magnetic Thin Films for Nonvolatile Memory Applications. J. Alloys Comp.732, 573–584. 10.1016/j.jallcom.2017.10.251
22
HaoA.JiaD.IsmailM.ChenR.BaoD. (2019). Controlling of Resistive Switching and Magnetism through Cu2+ Ions Substitution in Nickel Ferrite Based Nonvolatile Memory. J. Alloys Comp.790, 70–77. 10.1016/j.jallcom.2019.03.193
23
HaoA.JiaD.IsmailM.HuangW.ChenR.BaoD. (2019). Electric Field Induced Manipulation of Resistive and Magnetization Switching in Pt/NiFe1.95Cr0.05O4/Pt Memory Devices. Appl. Phys. Lett.114, 203502. 10.1063/1.5091841
24
HenningR. A.UredatP.SimonC.BloesserA.CopP.ElmM. T.et al (2019). Characterization of MFe2O4 (M = Mg, Zn) Thin Films Prepared by Pulsed Laser Deposition for Photoelectrochemical Applications. J. Phys. Chem. C123, 18240–18247. 10.1021/acs.jpcc.9b04635
25
HuW.ChenX.WuG.LinY.QinN.BaoD. (2012). Bipolar and Tri-state Unipolar Resistive Switching Behaviors in Ag/ZnFe2O4/Pt Memory Devices. Appl. Phys. Lett.101, 063501. 10.1063/1.4744950
26
HuW.QinN.WuG.LinY.LiS.BaoD. (2012). Opportunity of Spinel Ferrite Materials in Nonvolatile Memory Device Applications Based on Their Resistive Switching Performances. J. Am. Chem. Soc.134, 14658–14661. 10.1021/ja305681n
27
HuW.ZouL.ChenR.XieW.ChenX.QinN.et al (2014). Resistive Switching Properties and Physical Mechanism of Cobalt Ferrite Thin Films. Appl. Phys. Lett.104, 143502. 10.1063/1.4870627
28
HuangY.DongY.LiS.LeeJ.WangC.ZhuZ.et al (2020). Lithium Manganese Spinel Cathodes for Lithium‐Ion Batteries. Adv. Energ. Mater.11, 2000997. 10.1002/aenm.202000997
29
HuangZ.ChenQ.ZhaiY.WangJ.XuY.WangB. (2015). Oxygen Vacancy Induced Magnetization Switching in Fe3O4 Epitaxial Ultrathin Films on GaAs(100). Appl. Phys. Lett.106, 182401. 10.1063/1.4919862
30
HwangS.MengQ.ChenP. F.KisslingerK.CenJ.OrlovA.et al (2017). Strain Coupling of Conversion‐type Fe3O4 Thin Films for Lithium Ion Batteries. Angew. Chem. Int. Ed.56, 7813–7816. 10.1002/anie.201703168
31
IshibeT.UematsuY.NaruseN.MeraY.NakamuraY. (2020). Impact of Metal Silicide Nanocrystals on the Resistance Ratio in Resistive Switching of Epitaxial Fe3O4 Films on Si Substrates. Appl. Phys. Lett.116, 181601. 10.1063/1.5143960
32
IsmailM.HaoA.HuangW.LeeJ.KimS.BaoD. (2018). Coexistence of Unipolar and Bipolar Switching in Nanocrystalline Spinel Ferrite ZnFe2O4 Thin Films Synthesized by Sol-Gel Method. Appl. Phys. Lett.113, 152103. 10.1063/1.5052031
33
JiangK.SunB.YaoM.WangN.HuW.KomarneniS. (2018). In Situ hydrothermal Preparation of Mesoporous Fe3O4 Film for High-Performance Negative Electrodes of Supercapacitors. Microporous Mesoporous Mater.265, 189–194. 10.1016/j.micromeso.2018.02.015
34
KumbharS. S.MahadikM. A.ShindeS. S.RajpureK. Y.BhosaleC. H. (2015). Fabrication of ZnFe2O4 Films and its Application in Photoelectrocatalytic Degradation of Salicylic Acid. J. Photochem. Photobiol. B: Biol.142, 118–123. 10.1016/j.jphotobiol.2014.12.002
35
LabchirN.HannourA.HssiA. A.VincentD.AbouabassiK.IhlalA.et al (2020). Synthesis and Characterization of CoFe2O4 Thin Films for Solar Absorber Application. Mater. Sci. Semiconductor Process.111, 104992. 10.1016/j.mssp.2020.104992
36
LanY.LiuZ.GuoZ.RuanM.LiX. (2020). A Promising P-type Co-ZnFe2O4 Nanorod Film as a Photocathode for Photoelectrochemical Water Splitting. Chem. Commun.56, 5279–5282. 10.1039/d0cc00273a
37
LeiS.LiQ.-H.KangY.GuZ.-G.ZhangJ. (2019). Epitaxial Growth of Oriented Prussian Blue Analogue Derived Well-Aligned CoFe2O4 Thin Film for Efficient Oxygen Evolution Reaction. Appl. Catal. B: Environ.245, 1–9. 10.1016/j.apcatb.2018.12.036
38
LiR.RenX.ZhangF.DuC.LiuJ. (2012). Synthesis of Fe3O4@SnO2 Core-Shell Nanorod Film and its Application as a Thin-Film Supercapacitor Electrode. Chem. Commun.48, 5010–5012. 10.1039/c2cc31786a
39
LiY.HanW.SwartzA. G.PiK.WongJ. J. I.MackS.et al (2010). Oscillatory Spin Polarization and Magneto-Optical Kerr Effect in Fe3O4 Thin Films on GaAs(001). Phys. Rev. Lett.105, 167203. 10.1103/physrevlett.105.167203
40
LiY.HanX.YiT.HeY.LiX. (2019). Review and prospect of NiCo2O4-Based Composite Materials for Supercapacitor Electrodes. J. Energ. Chem.31, 54–78. 10.1016/j.jechem.2018.05.010
41
LiuX.-M.CuiX.DastafkanK.WangH.-F.TangC.ZhaoC.et al (2021). Recent Advances in Spinel-type Electrocatalysts for Bifunctional Oxygen Reduction and Oxygen Evolution Reactions. J. Energ. Chem.53, 290–302. 10.1016/j.jechem.2020.04.012
42
LüdersU.BarthélémyA.BibesM.BouzehouaneK.FusilS.JacquetE.et al (2006). NiFe2O4: A Versatile Spinel Material Brings New Opportunities for Spintronics. Adv. Mater.18, 1733–1736. 10.1002/adma.200500972
43
NarangS. B.PubbyK. (2021). Nickel Spinel Ferrites: A Review. J. Magnetism Magn. Mater.519, 167163. 10.1016/j.jmmm.2020.167163
44
NikamS. M.SharmaA.RahamanM.TeliA. M.MujawarS. H.ZahnD. R. T.et al (2020). Pulsed Laser Deposited CoFe2O4 Thin Films as Supercapacitor Electrodes. RSC Adv.10, 19353–19359. 10.1039/d0ra02564j
45
PanF.GaoS.ChenC.SongC.ZengF. (2014). Recent Progress in Resistive Random Access Memories: Materials, Switching Mechanisms, and Performance. Mater. Sci. Eng. R: Rep.83, 1–59. 10.1016/j.mser.2014.06.002
46
PhamT. N.HuyT. Q.LeA.-T. (2020). Spinel Ferrite (AFe2O4)-Based Heterostructured Designs for Lithium-Ion Battery, Environmental Monitoring, and Biomedical Applications. RSC Adv.10, 31622–31661. 10.1039/d0ra05133k
47
RaghavanL.PookatG.ThomasH.OjhaS.AvasthiD. K.AnantharamanM. R. (2015). Room Temperature Ferrimagnetism and Low Temperature Disorder Effects in Zinc Ferrite Thin Films. J. Magnetism Magn. Mater.385, 265–271. 10.1016/j.jmmm.2015.03.030
48
RajagiriP.SahuB. N.VenkataramaniN.PrasadS.KrishnanR. (2018). Effect of Substrate Temperature on Magnetic Properties of MnFe2O4 Thin Films. AIP Adv.8, 056112. 10.1063/1.5007792
49
SaguJ. S.MehtaD.WijayanthaK. G. U. (2018). Electrocatalytic Activity of CoFe2O4 Thin Films Prepared by AACVD towards the Oxygen Evolution Reaction in Alkaline media. Electrochemistry Commun.87, 1–4. 10.1016/j.elecom.2017.12.017
50
SaguJ. S.WijayanthaK. G. U.TahirA. A. (2017). The Pseudocapacitive Nature of CoFe2O4 Thin Films. Electrochimica Acta246, 870–878. 10.1016/j.electacta.2017.06.110
51
SchloemannE. (2000). Advances in Ferrite Microwave Materials and Devices. J. Magnetism Magn. Mater.209, 15–20. 10.1016/s0304-8853(99)00635-6
52
SunH.YanZ.LiuF.XuW.ChengF.ChenJ. (2020). Self‐Supported Transition‐Metal‐Based Electrocatalysts for Hydrogen and Oxygen Evolution. Adv. Mater.32, 1806326. 10.1002/adma.201806326
53
SuzukiY. (2001). Epitaxial Spinel Ferrite Thin Films. Annu. Rev. Mater. Res.31, 265–289. 10.1146/annurev.matsci.31.1.265
54
VadiyarM. M.BhiseS. C.PatilS. K.KolekarS. S.ChangJ.-Y.GhuleA. V. (2016). Comparative Study of Individual and Mixed Aqueous Electrolytes with ZnFe2O4 Nano-Flakes Thin Film as an Electrode for Supercapacitor Application. ChemistrySelect1, 959–966. 10.1002/slct.201600151
55
VadiyarM. M.KolekarS. S.DeshpandeN. G.ChangJ.-Y.KashaleA. A.GhuleA. V. (2016). Binder-free Chemical Synthesis of ZnFe2O4 Thin Films for Asymmetric Supercapacitor with Improved Performance. Ionics23, 741–749. 10.1007/s11581-016-1833-8
56
WangB.LiS.LiB.LiuJ.YuM. (2015). Facile and Large-Scale Fabrication of Hierarchical ZnFe2O4/graphene Hybrid Films as Advanced Binder-free Anodes for Lithium-Ion Batteries. New J. Chem.39, 1725–1733. 10.1039/c4nj01802h
57
WangM.SunY.ChenH.ZhangY.WuX.HuangK.et al (2017). Enhanced Photoelectrochemical Activity of Nanostructured ZnFe2O4 Thin Films Prepared by the Electrospray Technique. CrystEngComm19, 772–775. 10.1039/c6ce02497a
58
WangR.XuC.SunJ.GaoL.LinC. (2013). Flexible Free-Standing Hollow Fe3O4/graphene Hybrid Films for Lithium-Ion Batteries. J. Mater. Chem. A.1, 1794–1800. 10.1039/c2ta00753c
59
YaoH.NingX.ZhaoH.HaoA.IsmailM. (2021). Effect of Gd-Doping on Structural, Optical, and Magnetic Properties of NiFe2O4 As-Prepared Thin Films via Facile Sol-Gel Approach. ACS Omega6, 6305–6311. 10.1021/acsomega.0c06097
60
YuZ.MoussaH.ChoucheneB.LiuM.SchneiderR.WangW.et al (2019). One-step Synthesis and Deposition of ZnFe2O4 Related Composite Films via SPPS Route for Photodegradation Application. Nanotechnology30, 045707. 10.1088/1361-6528/aaedcd
61
ZhaoH.NingX.YaoH.HaoA.IsmailM. (2021). Facile Sol-Gel Method Derived Au Nanoparticles Decoration Nickel Ferrites Thin Films: Effect on Optical and Magnetic Properties. Mater. Chem. Phys.265, 124480. 10.1016/j.matchemphys.2021.124480
62
ZhaoQ.YanZ.ChenC.ChenJ. (2017). Spinels: Controlled Preparation, Oxygen Reduction/Evolution Reaction Application, and beyond. Chem. Rev.117, 10121–10211. 10.1021/acs.chemrev.7b00051
63
ZhaoX.MaoL.ChengQ.LiJ.LiaoF.YangG.et al (2020). Two-dimensional Spinel Structured Co-based Materials for High Performance Supercapacitors: A Critical Review. Chem. Eng. J.387, 124081. 10.1016/j.cej.2020.124081
Summary
Keywords
spinel ferrite-based thin films, controlled synthesis, performances, applications, future prospect
Citation
Hao A and Ning X (2021) Recent Advances in Spinel Ferrite-Based Thin Films: Synthesis, Performances, Applications, and Beyond. Front. Mater. 8:718869. doi: 10.3389/fmats.2021.718869
Received
01 June 2021
Accepted
28 October 2021
Published
24 November 2021
Volume
8 - 2021
Edited by
Ahmad Gholizadeh, Damghan University, Iran
Reviewed by
Karthik Ramasamy, UbiQD, Inc., United States
Derek Meyers, University of California, Berkeley, United States
Updates
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© 2021 Hao and Ning.
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*Correspondence: Aize Hao, h1061717965@163.com
This article was submitted to Thin Solid Films, a section of the journal Frontiers in Materials
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